The main objective of the proposed research is to measure and to correlate the integrated concentrations and production rate of various peptide and steroid hormones (HGH, insulin, glucagon, cortisol, 17-hydroxyprogesterone, etc.) in some physiological and pathological conditions. The integrated concentration of the hormone under consideration is measured in a pool of blood withdrawn at a constant rate utilizing a small portable pump connected to a heparinized catheter developed by the investigators. In addition, continuous monitoring of blood glucose is carried out by connecting the non-thrombogenic system to a glucose analyser. Efforts will be made to determine the clinical importance of these findings as far as diagnosis and treatment of conditions which in various ways can affect growth. BIBLIOGRAPHIC REFERENCES: Plasma Concentration of Aldosterone in Normal Subjects from Infance to Adulthood. Kowarski, A., Katz, H., and Migeon, C.J. J. Clin. Endocrinol. Metab. 38:489, 1974. Integrated Concentraton of Plasma Aldosterone in Normal Subjects: Correltation with Cortisol. Kowarski, A., de Lacerda, L., Migeon, C.J. J. Clin. Endocrinol. Metab. 40: 205, 1975.